Just looking for everyone's opinions on an engine build. What power do you think this should make, where do you think it should peak, and what kind of trap speed should be expected based on it being in a stick shift corvette, around 3100 with driver that went 142 in 1500 DA with 660whp std on a dynojet out of a sbe LS7, ported and milled LS7 heads, ported only MSD atomic with 103 tb, older BTR stage 3 LS7 cam (237/250, 646/632, 113) and 1-7/8 kooks headers.

New motor:

LSR Block, 427ci
Callies 8 cw Crank
Callies Extreme rods 4" stroke
Carillo 4.125 pistons (BLS1204-STD)
Mahle ring pack
Cam is a 250/264, 710/700 on a 113
Johnson ST2116LSR lifters (pre load set at .028 intake and .030 exhaust)
CT Porting CID LS7 with a 52cc chamber, 7mm valve stems (Titanium intakes still).
Static is around 14-14.5:1
Ironmask Maximus SR MSD with 112 tb
Pump E85

 

690rwhp, 7-7200 rpm , 146mph in the identical setup with the same conditions. That intake is the biggest limitation to the entire setup. Im in the same boat as boat as you because I have no choice but to run a msd or chop my hood which im not willing to do. You might be able to get past that 700rwhp mark but I have yet to see it done with the msd.

 

Friend of mine did 705 with the Maximus 112SR. 440", don't know the cam specs, Ironmask BR7s with the 2.245" intake valve, GZ Motorports vacuum pump, wet sump conversion which is supposedly good for 10 whp or so.

 

Recently saw some test data posted by Gromm Racing on their instagram. Maximum did very well.

Did some intake manifold testing today on the LS7-based combo.

Here’s the setup:

Factory LS7 block, crank, and titanium rods with ARP bolts

JE drop-in pistons (thermal barrier crown + skirt coatings), 1.2/1.2/3mm ring pack

Factory LS7 heads with my CNC port program

Factory Ti intake valves, stainless exhausts, dual spring kit with Ti retainers

Texas Speed roller tip rockers, 3/8” .080” wall pushrods

Comp Cams EVO hydraulic roller lifters

Custom cam: 24x/25x, .7xx” lift, 113.5 LSA, straight up — no advance

Factory LS7 pump, ARE dry sump pan

11:1 compression, heads cleaned up .005”, flat tops with valve reliefs

Intake Manifold Testing Results:

Intake 1: Holley Hi-Ram
Peak Torque: 631.8 lb-ft @ 5200 RPM
Peak HP: 754.5 @ 7300 RPM
BSFC: .468 at peak power
RPM spread (TQ–HP): 2000 RPM

Intake 2: TSP Titan w/ twin 4150 throttle bodies
Peak Torque: 632.7 lb-ft @ 5600 RPM
Peak HP: 764 @ 7400 RPM (highest of the test)
BSFC: .489
RPM spread (TQ–HP): 1800 RPM

Intake 3: Iron Mask Maximus (MSD style)
Peak Torque: 653 lb-ft @ 5000 RPM (highest of the test)
Peak HP: 754.2 @ 7200 RPM
BSFC: .430 (best of the test)
RPM spread (TQ–HP): 2200 RPM

 

The btr ls7 intake has showed some promise for higher rpm stuff.

 

Here is something similar with less compression, less cam 24X/25X on a 114 LSA, and ported stock heads. With the BTR manifold it made 69x STD.

I would expect something with more compression, CID heads, more cam etc.. to make ~730 STD on Pump E with a BTR manifold.

 

The car runs well, but their numbers are a bit inflated.

I have a similar setup, ported heads, my cam is slightly bigger than the RPM B3, I just put a BTR Trinity on today and it's certainly not making 690 whp on most dynos. It runs great but I'm waiting for my Maximus 112SR to be done and I fully expect the Maximus to outperform the Trinity from top to bottom.

 

you already know this, but it should a bit better than mine considering the CI, cam and Intake package are nearly identical but he's got better heads and more compression than me. 144-145mph should be the trap if weight/weather is the same at one of our local tracks up here. definitely potential to be 145+ if it manages to get enough air!

 

That is what I think as well. I think it could use more cam with the compression.

 

maybe just a tad, but unless he is changing intakes, i wouldn't put much into stock into the cam waking the engine up drastically. the maximus is great, but it still only makes good power to 7200ish. no point in camming the engine for higher rpm if the intake won't let it happen. If i was going to do mine again, i'd actually probably take a couple more degrees out of the intake side now that i have the data.

 

He is still on the fence about the Trinity too. Cesar has a v2 at the shop he could port and get out the door if need be. His problem though still is the stock ecu, so I feel the maximus is the one to stay with. So if the thing peaks at 7-7200, shifting it at 8-8200 will keep him in his power range. Comparing both of your dyno graphs, they damn near overlay until his fell off at 6100.

 

Definitely wouldn't do the trinity if he wants to primarily drag race. It'd make more top end but the mid range losses would likely offset the top end. If he's sticking to mostly rolls, trinity would probably work well.

Another reason not to get crazy with the cam's intake duration.. The MSD won't like shifted above 7500. It falls off too hard to justify spinning it that high. Every single pass i made last year shifting above 7500 et'd and mph'd slower than shifting 7200-7500. the exception are my 60-130 pulls, shifting once from 2-3 and taking 3rd to 8192 was always faster than shifting a second time since 130 happens in an awkward spot for me. either way, my point is that if he is going to make a significant cam change, it should be in conjunction with a computer change for more RPM and a square root fab/shearer hi-ram combo.

 

Trinity should be outpacing the MSD by 6000 rpm. How much are you below 6000 rpm on the drag strip?

 

Trinity won't outpace an Ironmask short runner MSD until closer to 7k. His modded MSD basically mimics a standard hi-ram, but with better down low torque.

 

Even over 7000 it still might not catch up. Ironmask posted a dyno graph on Instagram about a year ago that showed the Maximus 112SR beating a ported Trinity with a 112mm throttle body all the way out to 7500 or 7600 where they were about to intersect. No idea if it had V1 or V2 runners on it though or how big of a difference that would make. I also have no idea what the rest of the setup was, but I'm guessing it was a pretty hot setup.

 

Man I feel it gets really hard to compare at a certain level. One engine shows one result, another completely different.

The Maximus is a badass piece for sure. And nice it doesn’t heat soak like the others.

 

How are they inflating #s on a Dynojet?

Do you have proof of this?

 

How? I don't know for sure, and I'm not saying they do it intentionally, but they do use STD instead of SAE. Usually their stock intake manifold setups make around 620-630 whp, but I've never seen anyone else do that. The RPM B3 cam is pretty decent, but it isn't magic.

I'm also certain that my car is not making anywhere close to 690 whp with my BTR Trinity. I have the V1 runners not the V2 runners, but I really doubt the V1 runners are going to be down 60 hp compared to the V2 runners. The other day on Facebook, Brian Tooley told someone with a 1000 whp setup that he might pick up 20 hp switching from V1 runners to V2 runners. Probably more like 10-12 on a heads/cam LS7 I would imagine.

 

The V1 vs the V2 is a big difference from what I have seen. Haven't seen power figure differences, but the cars were very lazy on the V1 and not running the times or mph compared to the V2 cars.

 

My guess is that the injectors were flooding the runner walls and causing a lot of transient fueling issues, similar to what the holley ultra low ram was doing.